Apparatus for simultaneously polishing both faces of a moving ribbon of glass



March 10, 1953 R. H. GOLIGHTLY 2,630,653

APPARATUS FOR SIMULTANEOUSLY POLISHING BOTH FACES OF A MOVING RIBBON 0F GLASS 2 SHEETS-SHEET 1 Filed May 26, 1951 Nmik March 10, 1953 R. H. GOLIGHTLY 2,630,658

APPARATUS FOR SIMULTANEOUSLY POLISHING BOTH FACES OF A MOVING RIBBON OF GLASS 2 SHEETS-SHEET 2 Filed May 26, 1951 Attorneys Patented Mar. 10, 1953 APPARATUS FOR SIMULTANEOUSLY POL- ISHING BOTH FACES OF A MOVING RIB- BON OF GLASS Robert Henry Golightly, Rainford, England, assignor to Pilkington Brothers Limited, Liverpool, England, a British company Application May 26, 1951, Serial No. 228,388 In Great Britain June 2, 1950 8 Claims.

This invention relates to apparatus for simultaneously polishing both faces of a movin ribbon of glass.

Apparatus for simultaneously polishing both faces of a moving ribbon of glass usually comprises coaxial polishing tools which operate simultaneously on both faces of the ribbon. Each tool comprises a plurality of spaced polishing discs mounted on a frame which is rotated on an axis perpendicular to the ribbon, the discs being arranged at equal radii from the axis of the tool.

In operation, the lower tool as a whole serves as a support for the glass against the pressure exerted by the discs on the upper tool and the tools have an operative diameter which is slightly greater than the width of the ribbon of glass, that is to say, as the discs on the tools revolve about the axis of the tool they successively overlap of the edges of the glass.

During their respective rotations, discs on the upper and lower tools may pass simultaneously the points at which they overlap each edge of the glass. When this happens a lower disc is overshadowed by an upper disc during the period of overlap.

Each disc of the tools carries a felt pad and a rouge suspension is fed between the discs and the glass in order to provide a suitable polishing medium, and as the discs overlap the edge of the glass the ribbon edge has a tendency to scrape the felts, and while the action is helpful in removing hard and dry rouge from both sets of felts, the spreading of fresh rouge suspension over the whole of the pad surface of the lower set of discs is extremely uneconomical because of the spacing of the discs and because of the angular velocity which results in a considerable waste of the suspension flowed to the pads, though no difficulty arises in applying rouge suspension to the set of discs on the upper tools through pipes which give a flow on to the upper face of the glass.

The main object of the present invention is to provide an economical and simple means for distributing rouge suspension to the lower discs of a polishing machine of the kind just referred to.

Accordingly, the present invention comprises a unitary device for conducting a rouge suspension to the set of polishing discs on the lower tool of a pair of coaxial polishing tools, between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, comprising a series of parallel flat tunnels communicating with a pan to which the suspension is dribbled, the free ends of the tunnels being disposed in echelon in the direction of rotation of the lower tool so that rouge may be spread on the overlaps at different radial distances from the centre of the discs, the said free ends being cut obliquely to the grooves so that the moving discs tend to pull the rouge from the extreme ends of the tunnels as they pass thereunder.

Such a device is used at each edge of the glass, that is to say for each pair of coaxial polishing tools a device is arranged at each end of a line at right angles to the path of the glass and containing the axis of the tools, the oblique ends of the opposed devices being so disposed as to be parallel or substantially parallel to one another, and Where tools are employed running in contra senses, right hand and left hand devices will be required so that at each edge of the glass the polishing discs are always running away from the mouths of the channels of the respective devlces.

Accordingly, four advantages arise from the employment of tunnels in accordance with the invention. First, the rouge prescribed for the lower tools in passing through the tunnels cannot be picked up by the set of discs on the upper tool; second, as the supply of rouge to the pan is dribbled into the pan there is only a trickle down the tunnels; third, owing to the production of a trickle flow, loss of rouge during the intervals between the discs reaching the device is minimised, yet the whole passage of the set of discs on the lower tool under the device engen ders an adequate flow of rouge to the surfaces of each; and fourth, the oblique ends of the tunnels are maintained clear of caked rouge by reason of the position of the device in relation to the sense of rotation of the lower tool. The economic supply of rouge without appreciable waste is due to the natural flow along the tunnels being governed by the shallow depth of the rouge collected in the pan.

The unitary device constructed according to the invention advantageously comprises tunnels constituted by grooves cut out of the upper face of a plate and a cover for each of the grooves inset on the upper face of the plate. The upper face of the plate may be recessed along each side of each groove to receive an individual cover which is thus inset within the upper face of the plate. Alternatively, a single cover may be employed and in this case the upper face of the plate is rabbetted lengthwise just outside each outer groove so that the single cover is inset on the upper face of the plate. The covers may be 3 soldered to the plate or removably fixed thereto, for example by counter-sunk screws.

The free ends of the tunnels are preferably shrouded from the discs of an upper tool by the ends of the grooves being cut back from the oblique end of the plate; thereby dry rouge dropping off the upper tool is prevented from entering the tunnels.

Where, however, tools are employed in which the upper and lower tools of a pair are rotating in opposite directions, it is preferred to bend down the overlapping cover or covers and at the same time eliminate the exposure of edges of the covers which might injure the upper pads, whilst the possibility of the cover scraping rouge from the discs of an upper tool is also eliminated. To this end the oblique end of the plate is bent slightly and the covers which are to be fitted are similarly bent before being applied, so that the edges of the covers approach the plane of the bottom of the grooves and to preserve the smooth plane of the underface at the extreme end the metal under the bent down edge is filed away or otherwise removed.

The pan employed in constructions according to the invention may be constituted by a perimeter wall being erected on the upper face of the plate, the width of the pan in that part of the wall passing the oblique end overlying the outer ends of all the grooves, so that the bottom of the pan comprises shallow sumps constituted by the outer ends of the grooves.

In order that the invention may be more clearly understood, one preferred embodiment thereof will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic elevation showing one pair of upper and lower polishing tools of a polishing apparatus operatively associated with rouge distributing devices according to the invention;

Figure 2 is a greatly enlarged fragmentary elevation, partly in section, showing a rouge distributing device according to the invention disposed in proximity to one edge of the ribbon of glass passing between the polishing discs;

Figure 3 is a plan view of the distributing device constructed according to the invention;

Figure 3a is a fragmentary plan view of the shortest groove with the cover removed for sake of clarity;

Figures 4 and 5 are side elevation and end elevation respectively of the device illustrated in Figure 3, and

Figures 6 and 7 are fragmentary views showing modifications hereafter referred to.

In the drawings, like references designate similar parts.

Referring firstto Figure 1 of the drawings, which shows one coaxial pair of tools of a polishing apparatus comprising a plurality of such pairs aligned in the direction of the movement of the glass I, the upper tool of the pair being indicated by the reference 2 and the lower tool by the reference 3. Each tool comprises a frame 4 carrying a set of individually rotatable polishing discs indicated at 5. In the construction illustrated, each set consists of six discs.

The coaxial frames 4 are respectively mounted on shafts 6 and I provided with worm gears 8 and 9. The worm gear 8 is driven by a motor 10, a coupling H being provided in the driving shaft to permit angular adjustment of the tool with respect to the motor. The other worm wheel 9 is similarly driven by a motor i2 through an adjustable coupling l3. Each polishing disc comprises a plate [4 on which a felt pad I5 is secured by an embracing member [6 as well known in the art.

As the tools are rotated the discs move in an annular path of which the outside diameter is herein referred to as the effective diameter of the tool and it will be observed, as most clearly shown in Figure 2, that the effective diameter of each tool is greater than the width of the ribbon of glass passing between the two sets of tools, so that all the discs of both sets overlap each edge of the ribbon of glass as the tools rotate.

The upper tools are fed with rouge by providing supply pipes which discharge the requisite amount of rouge on to the glass so that it is taken up by the rotating discs, but the supply of rouge to the discs on the lower tool is, according to the invention, obtained by a device which is inserted in the space at each edge of the ribbon of glass which is demarked by the path of movement of the two sets of discs and the respective edge of the glass.

The device for supplying rouge to the lower felts in accordance with the invention comprises a thin plate ll, for example of brass, which has three parallel grooves l8 milled out of the upper surface of the plate, and on the plate is erected a peripheral wall 19 which with the plate constitutes a pan into which rouge suspension is dribbled from a pipe 20, the level of the rouge being indicated at 2! in Figure 2.

The grooves l8, as most clearly shown in Figure 3, open into the pan so that the contents of the pan are dispersed through the three parallel grooves which, being shallow, confine three striplike layers of rouge which trickle along the grooves.

The plate I! is secured by a bracket 22 to a splash wall 23 which runs lengthwise of the polishing apparatus and the length of the plate is such that it extends into the space demarked by the paths of the two sets of polishing discs and the respective edge of the ribbon of glass passing between the two sets. This arrangement of the plate overlying the overlapping part of the disc is clearly illustrated in Figure 2.

The free end of the plate is cut away obliquely, approximately at an angle of 45 to the edge of the plate, and it will be observed that the oblique end is so arranged that as the lower tool rotates in the direction indicated by the arrow 24 in Figure 3, the respective polishing discs pass across the longer edge of the plate first, and then pass under the oblique end of the plate.

Each of the grooves l8 extends up to the oblique end to the plate so that the rouge trickling down the grooves is deposited on the overlap at different radial distances from the centre of the disc.

Over each groove a cover 25, set on the upper face of the plate is provided, so that there is no possibility of the discs of the upper tool picking up the rouge intended for the discs in the lower tool, and as the lower tool rotates the discs thereof tend to pull the rouge from the extreme ends of the tunnels.

In view of the low head of the volume of rouge collected in the pan Hi, there is only a trickle of the rouge through the tunnels so that in the intervals between the discs of the lower tool passing under the plate ll there is only a minimum loss of rouge from the device, whereas the passage of the discs under the oblique ends of the device effects an adequate supply of rouge to the disc.

The ends of grooves 18 towards the free end of the device are cut back, as indicated at 18a in Figure 3, with respect to the oblique end of the device so that the respective covers overlap or shroud the ends of the grooves and thereby obstruct the entry into the tunnels of dry rouge falling from the discs of an upper tool.

In order to obtain exactly the same conditions of feed of rouge to the discs on the lower tool at each edge of the ribbon of glass, two devices as just described are preferably employed, one at each end of a line passing through the axis of the tools at right angles to the edges of the glass, so that a plate ll carrying a pan and formed with tunnels as already described is mounted on each splash wall 23 so that the pair of devices and the axis of the co-operating tools between them are in alignment, the oblique ends being disposed in parallel relation. If a pair of coaxial tools are rotating in the direction indicated by the arrow 24a in Figure 6, then the devices have to be shaped as shown therein so that the oblique edge will bear the same relation to the direction of rotation of the tools and the latter are moving in a direction away from the oblique ends of the devices.

From the foregoing, it will be observed that in a polishing machine constructed according to the invention all the discs on the lower tools are rotating in a direction so that they are always moving away from the oblique ends of the respective two devices, thereby protecting the ends of the tunnels in the devices from being choked by caked rouge and in each case deriving an adequate supply of rouge from the trickle arriving at the ends of the tunnels.

Instead of providing individual covers for the grooves l8, a single cover 251) may be provided as indicated in Figure 6. To this end the plate is rabbetted near each longitudinal edge as indicated at I'la so as to seat between the edges a single cover 251) which is thereby inset on the upper face of the plate i1.

Where the device is intended to be employed between coaxial polishing tools of a pair which rotate in opposite directions, the covers 25 or the cover 251) are bent towards the plane of the lower polishing discs so as to prevent the discs which are rotating towards the oblique edges of the device from forcing rouge into the tunnels. To this end the free edge of the plate I! is bent down and the underface is filed or otherwise treated as indicated in Figure '7 to preserve the plane of the underface of the plate I7 and the cover 251) is first bent at its end intended to overlie the oblique end of the device before it is applied thereto so as to conform to the shape at the to the edge of the glass, the ends of the device,

being obliquely cut in opposite directions so that the rotating tools are always moving away from the two opposed oblique ends of the devices.

From the foregoing, it will be observed that the invention comprehends a novel method of feeding rouge to rotating polishing discs operating against the underface of a moving ribbon of glass, which consists in collecting a shallow 6. volume of the suspension and constraining a dispersal of the collected suspension in thin striplike layers of varying length so as to deposit rouge on the overlap of the discs beyond the respective edge of the ribbon of glass at varying radial distances from the centre of the disc, the head of the collected volume being not larger than is required to cause a trickle of the liquid from the ends to the layers and dripping fresh suspension to the collection in compensation for loss of volume due to the dispersal.

Iclaim:

1. For conducting a rouge suspension to the set of polishing discs on the lower tool of a pair of coaxial polishing tool-s between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising a pan to which rouge suspension is dribbled, and a plate-like member having a series of flat tunnels each comprising a top, a bottom and side walls, one end of each tunnel communicating with the pan to receive rouge therefrom, the other ends of the tunnels being disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at different radial distances from the centres thereof, the walls of said plate-like member adjacent the tunnels at said other ends thereof being out obliquely to the through'ways of the tunnels so that the moving discs tend to pull rouge from said other ends of the tunnels as they pass thereunder.

2. For conducting a rouge suspension to the set of polishing discs on the low-er tool of a pair of cc-axial polishing tools between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising .a pan to which rouge suspension is dribbled,'a grooved plate having one end con tiguous with the bottom of the pan, the grooves being flat grooves extending lengthwise of the plate to receive rouge from the pan and guide it towards the overlaps of the lower discs, the other end of the plate being cut obliquely to said grooves so that the delivery ends of the grooves are disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at diiferent radial distances from the centres thereof and the moving discs tend to pull rouge from said delivery ends as they pass thereunder, and a cover for each said groove inset in said plate.

3. For conducting a rouge suspension to the set of polishing discs on the lower tool oi a pair of co-axial polishing tools between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising a pan to which rouge suspension is dribbled, and a plate-like member having a series of flat tunnels each comprising a top, a bottom and side walls, one end of each tunnel communicating with the pan to receive rouge therefrom, the other ends of the tunnels being disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at different radial distances from the centres thereof, the walls of said plate-like member adjacent the tunnels at said other ends thereof being cut obliquely to the throughways of the tunnels so that the moving discs tend to pull rouge from said other ends of the tunnels as they pass thereunder and the bottom wall of each tunnel being out back fora short distance from the oblique end thereof so that said other ends of the tunnels are shrouded from the upper tool by the top walls of the tunnels.

4. For conducting a rouge suspension to the set of polishing discs on the lower tool of a pair of co-axial polishing tools between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising a pan to which rouge suspension is dribbled, a grooved plate having one end contiguous with the bottom of the pan, the grooves being flat grooves extending lengthwise of the plate to receive rouge from the pan and guide it towards the overlaps of the lower discs, the other end of the plate being cut obliquely to said grooves so that the delivery ends of the grooves are disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at different radial distances from the centres thereof and the moving discs tend to pull rouge from said delivery ends as they pass thereunder, and a cover for each said groove inset in said plate, the pertions of said plate forming the bottoms of the grooves being out back for a short distance from the oblique end of the plate so that the delivery end of a groove is shrouded from the upper tool by the cover therefor.

5. For conducting a rouge suspension to the set of polishing discs on the lower tool of a pair of co-axial polishing tools between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising a pan to which rouge suspension is dribbled, a grooved plate forming the be tom of said pan and extending lengthwise therefrom, the grooves being fiat grooves extending lengthwise of the plate to receive rouge from the pan and to guide it towards the overlaps of the lower discs, the end of the plate remote from the pan being cut obliquely to said grooves so that the delivery ends of the grooves are disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at different radial distances from the centres thereof and the moving discs tend to pull rouge from said delivery ends as they pass thereunder, and a cover for each said groove inset in said plate.

6. For conducting a rouge suspension to the set of polishing discs on the lower tool of a pair of coaxial polishing tools between which tools a ribbon of glass is continually advanced, and which lower set of discs overlap in succession the edges of the moving ribbon of glass, a unitary device comprising a pan to which rouge suspension is dribbled, a grooved plate forming the bottom of said pan and extending lengthwise therefrom, the grooves being fiat grooves extending lengthwise of the plate to receive rouge from the pan and to guide it towards the overlaps of the lower discs, the end of the plate remote from the pan bein cut obliquely to said grooves so that the delivery ends of the grooves are disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge on the overlaps of the lower discs at different radial distances from the centres thereof and the moving discs tend to pull rouge from said delivery ends as they pass thereunder, and a cover for each said groove inset in said plate, the portions of said plate forming the bottoms of the grooves being out back for a short distance from the oblique end of the plate so that the delivery end of a groove is shrouded from the upper tool by the cover therefor.

7. In apparatus for simultaneously polishing both faces of a continually moving ribbon of glass, the combination with co-axial upper and lower tools each carrying a set of polishing discs which as the tools rotate move through an efiective path of a diameter greater than the width of the glass so that the discs successively overlap the edges of the glass, of means for feeding rouge to the discs of the lower tool and consisting of a pair of unitary devices each comprising a pan to which rouge is dribbled and a series of parallel flat tunnels each comprising a top, a bottom and side walls, one end of each tunnel communicating with the pan to receive rouge therefrom, the other ends of the tunnels being disposed in echelon in the direction of rotation of the lower polishing tool to spread rouge 0n the overlaps of the lower discs at different radial distances from the centres thereof, the Walls of the tunnels at said other end thereof being cut obliquely to the throughways of the tunnels so that the moving discs tend to pull rouge from said other ends of the tunnels as they pass thereunder.

8. A method of feeding rouge suspension to the set of polishing discs on the lower tool of a similar coaxial pair of tools, the set of discs on the lower tool being set in coaxial relation with the discs on the upper tool, the coaxial pair of tools simultaneously operating on both faces of a moving ribbon of glass, consisting in collecting a shallow volume of the suspension and constraining a dispersal of the collected suspension in thin striplike layers of varying length, feeding the dispersal suspension between the opposed pairs of discs so as to spread rouge suspension on the overlap of the disc of the lower tool beyond the respective edge of the ribbon of glass at varying radial distances from the centre of the disc and thereby spread the suspension across the overlap, arranging that the head of the collected volume is such as to cause a trickle of the suspension from the ends of the layers, and dripping fresh suspension to the collection in compensation for loss of volume due to the dispersal.

ROBERT HENRY GOLIGHTLY.

REFERENCES CITED UNITED STATES PATENTS Name Date Griifin June 26, 1935 Number 

